1. Field of the Invention
This invention pertains generally to the field of stoneworking, and more specifically to sawing, shaping and polishing of stone or similar material. Various specific manifestations of the invention include a portable tool mount which is configured to support and guide a saw, an abrading rotary disk tool, or other stoneworking equipment or tools; an edging apparatus for stone and other hard materials; and a rotary disk abrading tool provided with a member or a holder to facilitate the application of the tool to the workpiece.
2. Description of the Related Art
Stoneworking is a very old art, dating back to the days of cave dwellers when man is presumed to have first taken shelter within a stone structure. However, the age of the art should not be confused with the level of technology in use today. The desirability of stone in dwellings, for various monuments and markers, and in many other applications continues to be great, owing to intrinsic hardness and resistance to the elements, a wonderful array of diverse natural and enhanced appearances, temperature resistance, thermal mass, low thermal expansion, and other desirable and unusual features. Consequently, much modem technology has been applied to further the provision of stone into the marketplace.
Stone is quarried in large blocks from mines and is normally next cut into thinner slabs. These slabs are polished on one surface and then typically sold into commercial or construction applications. Exemplary construction applications, though not by any means all-inclusive, are wall surfaces and decorations for both interior and exterior, trim, fireplaces, flooring, table tops, and counter tops. Rarely will the polished slab have the exact dimensions required for a given project. Consequently, the slab must be cut to fit the application. Depending upon the application, once the slab has been cut, the edge may additionally need to be finished, which may include leveling, shaping and polishing steps. Shaped and polished edges are typically created by grinding the surface with increasingly finer grits of abrasives. The abrasives are normally cooled with a fluid, typically water. As is known in the industry, the cutting, shaping and polishing operations release a large quantity of abrasive in the form of slurry and dust which can be quite detrimental to machines and equipment which are not designed to withstand the erosive environment.
Where large quantities of stone are to be cut and polished, relatively massive equipment has been designed and constructed which facilitates the cutting and polishing operations. These machines are generally designed to have enormous mass, which makes the tools much more rigid and also less susceptible to vibration and flexure that may otherwise occur. While these tools are well suited for operations where stones may be readily transported to the machine, they clearly have no utility for stones to be worked in situ at a construction location or the like. Furthermore, these machines tend to be extremely expensive, and so custom production on this type of machine results in undesirably large amounts of very expensive idle time. Not only do stones need to be changed for custom production, but the machine will also typically require reconfiguration and/or realignment for the custom job. Furthermore, the transport of a stone to and from a construction site to effect the custom work is not only expensive and the source of much delay, but the likelihood of an accident which destroys the stone is much greater with the additional transport. Finally, these large machines tend to be cost-prohibitive for a smaller shop that is not continuously using the machine. Exemplary patents that illustrate large commercial stone working machines include Adams in U.S. Pat. Nos. 3,164,144; 4,228,617 to Bando; U.S. Pat. No. 5,482,026 to Russell; U.S. Pat. No. 6,006,735 to Schlough et al; U.S. Pat. No. 6,073,621 to Cetrangolo; and U.S. Pat. No. 6,315,799 to Toniolo.
In an attempt to provide a more portable machine, which may, for example, be used directly at a job site, other artisans have proposed various rail systems which are clamped or otherwise anchored to stone or other hard material, such as concrete or glass. These rails may act as guides, such as in the U.S. Pat. No. 2,014,229 to Emmons; U.S. Pat. No. 4,552,122 to Kelly; U.S. Pat. No. 5,960,780 to Harris; U.S. Pat. No. 6,062,122 to Niemczyk; and U.S. Pat. No. 6,257,225 to Harris; or may alternatively act as a track which supports a trolley or the like. Exemplary trolleys are shown in U.S. Pat. No. 2,291,058 to Pohl; U.S. Pat. No. 3,323,507 to Schuman; U.S. Pat. No. 3,360,298 to Stoljarov et al; U.S. Pat. No. 4,054,179 to Destree; U.S. Pat. No. 4,979,412 to Anders; and U.S. Pat. No. 5,588,418 to Holmes et al. An additional devise uses a router with a profiled cutter for shaping and polishing edges. The profiled cutter is an abrasive, and is generally extremely expensive. With the nature of grinding, the abrasive on the profiled cutter is lost, generally unevenly. Consequently, a profiled cutter loses its shape with use and creates an edge which varies. This edge will not match the profile of the next cutter of finer grit, and so the next cutter will not make full contact to the edge of the stone. To achieve a polished edge, the mason will need to go back and rework spots or regions missed by mismatched profiles.
For a single cutting operation, many of these devices have found utility in the industry, and rightly so. Providing a guiding edge for an abrasive saw or other cutter such as is used to cut stone and other hard materials is of much benefit for custom applications or the like as are frequently required at a building site. When a section of flooring or wall requires custom cutting and fitting, it is not always practical or reasonable to expect a stone factory to size the stone to the needs in advance. Moreover, it may not always be possible to accurately predict the dimensions owing to variability such as spacing between adjacent stone and the like. Furthermore, the thickness of adjacent stones may vary somewhat unpredictably, and the leveling of the intersection of the two stones may be a very important finishing operation.
Unfortunately, many of these devices are designed for only very light duty. Where guides are used, they tend to lack the necessary resistance to abrasion from the stoneworking dust, and consequently have a limited life only suited for very light duty stone working. These machines also illustrate single tool applications. So, when a stone mason identifies the need for a tool to assist with the guiding of a stone cutting saw, he must purchase a guide for his saw. Later, when he elects to purchase a guide for another stone working tool such as a polisher or an edger, he must then purchase another piece of equipment. This single function tool holding and guiding is not highly desirable, and so many masons will perform all but the most complex or sizeable jobs by hand. As is all too well known, when work is completed by hand, there is much greater risk that the mason will err in the process, and this error is not readily remediated in stone. Consequently, the probability for unsightly imperfections or total loss of valuable stone, and the additional work required to remake a destroyed piece or repair an imperfection provides much incentive in the industry for better tools to reduce the dependence upon hand operations. Additionally, the freehand shaping and polishing is very strenuous and time consuming.
In addition to the limitations aforementioned, another shortcoming of the prior art apparatus is the ability to guide and form inside openings and corners such as are typically found in the installation of a kitchen or bar sink within a stone counter top. In order to cut this type of hole with inside corners, it is most desirable to drop the saw vertically onto the stone to begin the cut in a predetermined place. Where the design of the cutting guide requires the saw to traverse from an end or edge of the stone, such a guide will have no applicability to the holes created for sinks. Moreover, adjacent to the sink the stone will frequently be rather narrow. Where this is the case, in the prior art a reinforcement bar has been inserted into a small groove cut into the stone. The reinforcement bar may then be pressed into the groove and typically adhesively secured therein. However, the cutting of the trough must also occur in the middle of the stone, and in this instance a wider than ordinary cutting blade is most desirable, in order to only require a single passage of the tool through the stone in the formation of the trough.
What is desired then is a portable apparatus which enables a stone mason or worker of other hard material to purchase a single apparatus which will perform the precise guiding of diverse tools across the hard material. A need furthermore exists for an apparatus which will allow a mason at a job site to form precise inside holes, shapes and polished surfaces.
In a first manifestation, the invention is the combination track, trolley, crescent, and stoneworking tool for treating a stone slab. The track has a base with a first surface in contact with the stone and a second surface upon which at least one roller may travel in a path. A ridge extends longitudinally parallel to the path with first and second normal surfaces which extend in a first direction normal to the stone slab and in a second longitudinal direction. The trolley is supported on at least one roller which rolls on the second surface and has a second roller which rolls on the ridge first normal surface and a third roller which rolls on the ridge second normal surface. A tensioning member is movable to vary a distance between the second and third rollers from a first position which holds the rollers tightly against the ridge to a second position which allows the rollers to slide normal to the stone slab. The crescent is supported upon the trolley and has first and second crescent members each forming an arc about an edge of the stone slab. Each crescent member has an inside and an outside. There is additionally a space between the two crescent members within which the stoneworking tool operates. The tool has a tool support carriage for traversing the crescent and carrying the tool therewith along the arc.
In a second manifestation, the invention is a portable track and trolley for engaging a material to be worked and subsequently mounting a tool for working the material to the trolley, and then guiding the tool relative to material to be worked. A base has a first surface adjacent to a surface of the material and a second surface opposite thereto for supporting the trolley. A rail extends in a height from the material surface in a first normal direction and has opposed roller surfaces thereon defining a width, and extends longitudinally along a length. A trolley undercarriage has a first plurality of wheels maintaining a load a minimum distance normal to the material surface from the material surface that provide rolling contact between the wheels and the base. The undercarriage further has a second plurality of wheels engaging the rail on opposed roller surfaces. A tool carrier locating member locates a tool carrier relative to the trolley. A tool carrier engaging member operatively retains the tool carrier to trolley after engagement therewith. At least one removable fastener retains tool carrier to trolley.
In a third manifestation, the invention is a motor carriage for supporting a stoneworking tool in either an operative position or an inoperative position which is readily moved between the operative position and inoperative position. A sliding holder retains the stoneworking tool within motor carriage. A guide is provided, along which the sliding holder travels during movement. A link is provided between sliding holder and an anchor member of the motor carriage. A release pivots about a first axis and responsive thereto moves the link relative to anchor member and thereby moves the sliding holder relative to the anchor member at a first distance change per degree of rotation. The release pivots about a second axis and consequently moves the link relative to anchor member and thereby moves the sliding holder relative to anchor member at a second distance change per degree of rotation which is less than the first distance change per degree of rotation.
In a fourth manifestation, the invention is a guide for shaping, contouring and polishing an edge of a hard material through contact with a tool. First and second crescents wrap angularly about the hard material edge. A tool holder is provided between first and second crescents. A means for moving the tool holder relative to crescents follows an outline of the crescents. A means is also provided for engaging the tool with hard material.
Exemplary embodiments of the present invention solve inadequacies of the prior art by providing a portable trolley for carrying various tools, and a track which attaches directly to the stone and which simultaneously isolates the tool from the stone. A standard connection is provided which can readily accommodate a variety of diverse tools, using a keyway to ensure accurate and repeatable placement of the tools. A preferred contouring guide allows a tool to be moved through an arc, where the focal point of the arc may be set to produce an infinite variety of custom shapes.
A first object of the invention is to provide a portable tool guide for stone and other hard materials. A second object of the invention is to greatly reduce the hand labor required to custom finish a hard material. Another object of the present invention is to improve the precision of cutting and polishing operations. A further object of the invention is to provide the guide in a relatively small and compact package. Yet another object of the present invention is to enable rapid tool changes. Yet a further object of the invention is to provide a precision shaper using low cost and durable disc-shaped abrasives, to accurately produce a diverse number of edge profiles. Another object of the invention is the provision of a high quality, precision tool guide which is durable and still manufactured for a low cost. An additional object of the invention is to provide an apparatus that automatically adjusts for abrasive material lost from the cutter.